big chainring

Do these have any value? The crank that accepts the large single bearing Dura-Ace pedal. I think they were introduced in the late 70's. Are they collectible or just an odd cast-off.

23skidoo

DA Dyna-Drive cranks from about 81-83; Old Fat Guy knows more about them than I do but a decent set of them just went on eBay for well over $100; the pedals get fairly pricey too as well as the adapters that let you use a standard 9/16th threaded pedal.

Old Fat Guy

Alexi Grewal won the only American gold medal for road racing in 1984 using those cranks and pedals.

knoregs

I have a set of the pedals. I had the adapters but they seem to be MIA along with the cranks.

~kn

JohnDThompson 

At one time you could get adapters to use ordinary pedals with the Dyna-drive arms:

505oh505

these came on my univega. I had to lower my seat half an inch because the way the pedals are designed, your foot sits below the (pedals) axle centerline, where usually it was on top of the axle. weird.

cyclotoine

SO sweet. we just overhauled a 1981 kuwahara built apolo with the complete 1981 dura-ace group and I mean complete and original including stem and seatpost, original benotto tape too and the hubs are beautiful.. araya tubulars of course. The customer came in to upgrade it (his wifes bike) but we talked him out of it and he decided we should overhaul it and clean it up so he could hang it on his office wall... we all thought it a good decision.

afilado

Caterham, I think I have a NOS set of DA aX pedals I'll likely never use. If you're interested in them shoot me a PM.

J

Elev12k

Koga (Miyata) even had DynaDrive sizing frames. Below my 58DD. The length of a 58 bike, but a couple centimeters lower.



My lbs had adapters made for use with conventional pedals >>

bikemore 

Was there any purpose for the larger hole? I'm guessing Alexi Grewal might have won with different
pedals. And they only made them for 3 years.

randyjawa 

I have three or four sets of these pedals and one set of cranks that I am aware of in The Old Shed. Never had much use for them so far. Can't even say that I like the appearance all that much.

The pedal is pretty comfortable to use even with softer soled shoes, thanks to the large foot contact area.

T-Mar

The purpose of the Dyna Drive system was to have the pedal and shoe interface in the same plane as the centerline of the pedal axis. This provides an incredibly stable pedal platform without any tendency to tip. A cyclist expends energy maintaining pedal stability and Dyna Drive (theoretically) allowed you to divert this energy towards crank rotation.

However, to achieve this position for the interface you cannot have a long axle running the width of the pedal. The axle has to be located inboard of the pedal cage and therefore all the load has to be carried by bearings inboard of the cage. The best way to carry the increased load was to increase the number of bearings. Of course, this could still be achieved using a standard axle thread, but meant the bearings would be between the crank arm and cage, increasing the overall pedal width, which places the feet farther apart (Q-factor) and decreases pedaling efficiency. Shimano's solution to maintain Q-factor and carry the load was to use an oversize axle that allowed for more bearings and carried the bearings within the plane of the crankarm.

The Dyna Drive crankarms themselves were the stiffest crankset available at the time and combined with the matching pedals are the most under rated system of the era. Dyna-Drive made its debut on the 1980 Dura-Ace EX group and was subsequently added to Dura-Ace AX in 1981.

The original concept for the lowered shoe/pedal interface came from the Hi-E pedal of the late 1970s which used a standard axle thread.

big chainring

Thanks for the info guys. False alarm though. I was looking at a bike on ebay and thought it looked like the Dura-Ace crank, but it was just the angle at which the photo was taken.

bibliobob

That's one of the prettier bikes I've seen in a while.

divineAndbright

With all of todays fascination and red herring with stiffness and efficiency (and ugly/silly/overbuilt looking parts) you gotta wonder why this system hasn't had life breathed back into it yet.

23skidoo

+100 on that, mighty sweet ride

glynround

The Dura Ace 600 ax chain set was slightly longer than 170mm (it was 171.5mm), The larger bearing on the pedals (600ax) was offset to pedal axis thus giving approx. 4-5 mm extra length plus. It was only produced for a 3-4 year period Very early 1980's. it is more collectable now than ever and with pedal adaptors you can use modern clip in
pedals.
I may have a used one for sale as I am about to strip my 1982 time trial /road bike it is absolutely mint condition as i cleaned after every ride and probably spent more time using solvol autosol polishing it than using it, I am coming up to 75 and owned it from new but too fast for my brain responses so sadly time for new home if any one wants more info or details on this or the groupset please phone me, Glyn 01773 760236 (land line) based in Derbyshire

thumpism

I have a couple of the cranks, one racing (DA) and one touring (Deore), plus a couple of pairs of pedals, one pair NOS with clips and straps still in the box. Used to have several adaptors but gave them to guys who would actually use the cranks.

Bikerider007

Old thread but, the Shogun Tourer I am doing a build on soon has the original Deore Touring set-up with Dyna-Drive.

I have read the main reason it did not take off was being able to change pedals and that some of the bearings had wear issue. It sounds as though the system is advantageous but would require multiple manufacturers to be on board so a wide variety of pedals and cranks would be available.

Btw, still looking for a Mavic Module 3-36h 27 1/4". My rear has a couple cracks around spokes. May have to build as is for now.

thumpism

Of the two pairs of DD pedals I have, one has bearing problems. May only need adjustment but I have not investigated since I do not plan to use them.

There is a record of manufacturers who altered a facet of the industry with a "new standard" for certain elements (Shimano and the 130mm BCD for road rings; Sugino with the 110/74mm for touring) when everything that went before was one thing and everything after was the new, but DD honestly never looked like it would be one of them.

3alarmer 

...there was a guy on e-bay machining and selling the adapters from somewhere in Russia or eastern Europe as recently as last year. Might still be on there somewhere. I bought a pair, and they took a while to get here, but worked out fine.

T-Mar

That was the problem. Nobody liked the look of them. They were non-traditional. Consequently, very few gave gave them a chance. I don't know if Shimano's statement of power expenditure was true but I can vouch that they were more stable than a traditional pedal. The majority of people I've talked to who have actually owned and ridden them, thought they were great. A lot of people thought they would be harder to overhaul but they were actually easier.

Dyna-Drive reminds me a lot of SunTour's high normal front derailleurs, which worked great, but the lever motion was opposite to a standard front derailleur. A lot of people didn't like that. But anybody who had never ridden a derailleur equipped bicycle and started out on a Spirt or Compe-V had no issues with them. It was the traditionalists who killed both high normal and Dyna-Drive. Both were good concepts that worked well.

CO_Hoya 

His seller ID is olavinar, from Finland.

I also have his e-mail address somewhere if you need to contact him. I have no idea if he's still making / selling those adapters. I chatted with him about them a few years ago but never ended up buying any.

Iowegian

I've heard good things about the Dyna-drive from friends of the old racers here in Boulder too.

I have 2 of the adapters if anyone needs them. Unfortunately, they are both for the same side (left I think)

gugie 

This is another one of those "improvements" with no supporting data.

The claim that it is more efficient has me scratching my head. One would think you could rig up a motorized "test dummy" and compare output power at the wheel, publish the data, and patent it.